1. Field of the Invention
The present invention relates to improvement of the function of a memory card incorporating an IC card function, and in particular to improvement of a method of supplying power to the memory card.
2. Description of the Related Art
In recent years, a memory card having an IC card function and also being smaller than a Japanese business card has been developed. This memory card is inserted into a card-sized adapter, and is used as removable memory for a host device such as a cellular phone.
However, since the memory card itself does not have a power supply, it is necessary to provide means for supplying power to the memory card. In view of this, in a proposed method, power is supplied to the memory card from the host device such as electronic equipment, into which the memory card is loaded, and when supply of power from the host device is stopped, this fact is detected, and power obtained by electromagnetic induction from a non-contact communication antenna provided at the memory card is utilized (as disclosed in, e.g., Jpn. Pat. Appln. KOKAI Publication No. 2002-279378).
Furthermore, recently, the method of supplying power to a memory card from an electronic device serving as a host device into which the memory card is loaded has been varied. Therefore, regardless the type of the host device, it is necessary to appropriately supply power from the host device to the memory card.